Electronic shopping has become widely available, and many consumer items (e.g., products and/or services) are readily available for purchase via network sites, such as retail web sites. Typically, when a consumer buys an item from a network site, the consumer not only pays for the item itself, but also pays for the cost associated with shipping the item to the consumer. Such shipping cost is usually proportional to the weight of the item that is being shipped. To encourage consumers to shop via network sites, many retailers offer free shipping if the consumer makes a purchase that is over a certain dollar value. Alternatively, the retailers may offer a paid membership that may include free shipping as one of its benefits.